1. Field of the Invention
This disclosure relates to an exposure device and an image formation apparatus, and is suitable for application to electrophotographic printers (hereinafter also referred to as printers), for example.
2. Description of Related Art
In widespread printers as conventional printers, an electrostatic latent image is formed on the surface of a photoconductive drum by irradiating the drum's surface with light from an exposure device such as an LED head, which includes light-emitting elements such as light emitting diodes (LEDs) and a lens array, and then is developed to a toner image with application of toner to the electrostatic latent image.
Some of such exposure devices include, for example, a substrate with one of its surfaces equipped with an LED array chip having LEDs arranged linearly, a rod lens array configured to condense light emitted from an LED array chip, and a holder holding the substrate and the rod lens array such that the LED array chip on the substrate and the rod lens array face each other. In addition, in some exposure devices, an attachment is attached to the substrate so as to cover the other surface opposed to the one surface, and the substrate is fixed to the holder by bonding the holder and the attachment (see Patent Literature 1, for example).
In such an exposure device, the LED array chip mounted on the substrate emits light in an irradiation pattern based on an image to be printed. The emitted light is converged through the rod lens array, and the surface of a photoconductive drum disposed at a focus position of the rod lens array is exposed to the light, so that an electrostatic latent image is formed on the surface.    [Patent Literature 1] Japanese Patent Application Publication No. 2012-66499 (FIG. 5)